Housing heater



R. A. BROWN Aug. 6, 1935.

HOUSING HEATER Filed March 2Q, 1933 3 Sheets-Sheet l R. A. BROWN .HOUSING HEATER Aug. 6, 1935.

Filed March 20, 1933 3 Sheets-Sheet 2 AM%M% Qzzz,

Aug. 6, 1935.

R. A. BROWN HOUSING HEATER 3 Sheets-Sheet 3 FiledMarch 20, 1935 PatentedAug. 6, 1935 UNITED STATES PATENT OFFICE HOUSING HEATER Ray A. Brown,Rockford, Ill. Application March 20, 1933, Serial No. 661,808 20 Claims.(01. 219-47) This invention relates to a heater for heating housings onmotor vehicles principally with a view to facilitating servicing.

The present practice in cleaning out diflerential and transmissionhousings for replacing the lubricant is to use steam to loosen and clearout the lubricant, or to flush out the same with kerosene or gasoline.Both methods have serious objections. It is, therefore, the principalobject of my invention to provide a portable heater for application tothe housing to render the lubricant sufiiciently fluid by heating topermit easy drainage. An important feature of this heater is that itheats by the passage of magnetic flux back and forth through the housingwall, the heater being of an electromagnetic type operated preferably onalternating current, or on direct current using an interrupter.

Another object of the invention is to provide a heater of the kindmentioned constructed to promote convenience in application to thehousing to be heated, and so as to adapt the heater to use on diiferentsizes and shapes of housings.

Other objects and advantages of my invention will appear in the courseof the following 'detailed description, in which reference is made tothe accompanying drawings, wherein-- Figure 1 is a rear view of anautomobile showing the heater of my invention in position on thediiferential housing;

Fig. 2 is a view of the housing and heater on a larger scale showing theheater in vertical crosssection;

Fig. 3 is a side view of the heater;

Fig. 4 is a view similar to Fig. 2 but showing a heater of modified oralternative construction having adjustable jaws to accommodate a largerange of housings of diflerent sizes and shapes;

Fig. 5 is a side view of the heater illustrating how the jaws areadapted to conform themselves to the contour of the housing;

' Fig. 6 is another view similar toFigs'. 2 and 4 but showing a stillfurther modified or alternative construction;

Fig. 7 is a side view of the lower portion of the heater with a portionbroken away to permit showing the parts on a larger scale;

Fig. 8 is a cross-section oi Fig. '7,and

Fig. 9 is a horizontal section on the line 9-4 of Fig. 8.

Similar reference numerals are applied to corresponding parts throughoutthe views.

In Figure 1 the heater or my invention is indicated generally by thenumeral ID in position on the differential housing H of an automobilefor the purpose of making the lubricant therein sufficiently fluid byheating the wall of the housing, to permit easy drainage when the plugis removed. In other words, nothing foreign is allowed to get into thehousing and interfere 5 with good lubrication. Where steam was used,there was always some water left in the housing which in cold weatherwould freeze, and in any event, was objectionable for obvious reasons.Where kerosene or gasoline was used it got into 10 the working parts andkept lubricant from getting in so that the parts were improperlylubricated. The kerosene or gasoline also caused objectionable dilutionof the lubricant. Aside from the fact that the steam; kerosene orgasoline left the housing in an unfit condition, the use of such amedium was objectionable because of the amount of time consumed; theheater of my in-. vention performs the operation in a fraction of thetime. While I have shown the heater applied to a differential housing,it should be understood that it may also be applied to the transmissionhousing for a similar purpose or to the engine crank case either for thesame purpose,

or for the purpose of preparing a frozen up car for starting. Heaters ofthis type willfind use at air ports for heating the crank cases ofair-craft engines in preparation for flight, thereby reducing the fuelconsumption and time loss in warming up. It will further appear thatwhile I- have shown an automobile, the invention is applicable to anymotor vehicle.

The heater I0 is of an electromagnetic type connected by means of asuitable extension cord I3 with an electric light socket in an A. C. orD. C. line with a view to heating the wall of the housing by the passageof magnetic flux back and forth through the wall. In a D. C. circuit itis apparent that an interrupter has to be used in order to securereversal of the flux, or simply inter- 40 mittent flux. At present, Iprefer the use of alternating current because it avoids any condition ofresidual magnetism in the part heated and seems to heat moreefliciently. Reversal of direct current would, of course, give the sameadvantage. Experiment has shown that it takes but a few minutes to heata cold housing sumciently to render the lubricant therein fluid so thatit may be drained out easily. The heater, as best appears in Fig. 2, hasa laminated core I, the pieces of which are placed at-right angles toeach otherv and suitably riveted together, as indicated at II, the outerends of the pieces having right angle portions l6 riveted together as atI! and forming the jaws for application to the wall of the housing. InFig. 2 I have indicated flux lines to give a better idea. of the way inwhich the heater works. Two coils are indicated at I8 on the two legs ofthe core l4. These are suitably connected togethereither in series orparallel, and, of course, have connection with the wires of theextension cord H3. The housing IQ of the heater is of nonmagneticmaterial and made in two pieces, as appears in Fig. 3 so as to permitassembling on the heater from opposite sides. Any suitable means may beemployed for fastening the housing sections together. Hooks 20 areformed on the housing sections topermit suspension of the heater on therear axle by chains or cables, as indicated at 2 I. When the heater isbrought into place from a pit or where the differential housing is highenough to permit, blocks or a jack may be provided to support the heaterwith or without the chain or cable. In that event, the flat surface 22on thebottom of the heater is used for engagement of the blocks, orjack. The plunger of a jack is indicated in dotted lines in Fig. 2 inengagement with the surface 22. Any pressure exerted on the surface 22is transmitted directly to the core l4 because of the fact that thecrotch of the core fits into a right angle pocket 23 in the bottom ofthe housing. There is, therefore, no danger of distortion if more thanthe necessary pressure is brought to bear. Sufiicient space is left inthe housing l9 between the coils l8 and alongside the core I4 to permitmounting a switch 24 directly on one of the housing sections. See Fig.3. The lever 25 of the switch 24 projects from the housing forconvenient operation, and has a projection 26 alongside the same toserve as a guard to prevent damage tothe switch and accidental openingor clpsing 'of the circuit by something coming in contact with theswitch lever. When a heater of the present construction is so designedto bring the jaws l8 near the axle bearings at the ends of the housingll, heat will be transmitted along the axle sections to the differentialgearing so that the lubricant thereon will become fluid and drain oft.However, it may be found desirable to provide a heater with adjustablejaws to permit placing them in the most advantageous position ondifferent sizes and shapes of housings. A heater of such construction isshown in Fig. 6, to which attention is now directed.

This construction also willffacilitate application ings and crank of theheater to transmission ho cases. Due to the fact that the heaterconsists of hinged sections, separate housings l9a and l--b are providedfor the coils on the core connected with the extension cord 13. The coresections lla and M-b extend'from the lower end of the housings as shown,and have through bolts 38 and 31 extended therethrough to provide pivotsas well as clamping means. Links 38 interconnect the bolts at the frontand back and are received between the arms 39 of a yoke 48, throughwhichthe bolt 36 extends, as indicated in Figs. '7 and 9. By providingtwo pivots at 36 and 31 I am enabled to get away from thecondition-illustrated in Fig. 5 on heater Ill; both sections of'the corecan be made solid without any air spaces between laminae. As shown inFig.

irthe pieces of the one core section have the center, and the matingpieces on the other core section have their lower ends cut out on acorresponding arc 42, to permit the angular adjustment of the sectionI4b about the bolt 31 as a center so as to widen or shorten the distancebetween the jaws Iii-a. Whenthe core has been adjusted as desired, thewingnuts ll on the bolts 36 and 31 can be tightened to clamp the partsrigidly in adjusted position. The bottom of the yoke 40 provides a placefor engaging a jack or block to support the heater. Hooks 20 can beprovided for suspension of the heater on the housing. The heater I0shown in Fig. 4 is another one having adjustable jaws, and attention isnow directed to Figs. 4 and 5. I The heater I0 has a laminated core Hi,the pieces of which are made to extend the full length of the housing l9and to project from opposite ends thereof for attachment thereto ofjointed adjustable jaws Hi. The jaws I6 are formed in two laminatedsections 21 and 28, the former pivoted to the ends of the core M, asindicated at 29, and the other section pivoted to the end of the firstsection, as indicated at 30. Through bolts are provided for the pivotshaving heads on one end and wing nuts 3| on the other end to the piecesof the jaw section 28 to permit the pieces to slide endwise with respectto one another and relative to the bolt 30 to arrange the ends in an areor otherwise in" order to engage quite a large area on the surface ofthe housing, regardless of its curvature or other peculiar shape. SeeFig. 5. The nuts 3| on the bolts 30 would; of course, have to beloosened sufiiciently to permit sliding of the pieces in the mannerstated, and once the pieces were arranged as desired, the nuts could beretightened.

In order to relieve the jointed jaws l6 of pressure that might 'besufficient to force them The heater l0-a has the laminated core thereoutof position, I have provided a middle projection 34 on each of thepieces of the core It for engagement with the bottom of the housing. Thesections of the housing l9 of the heater are formed asappears at 35 tohave abutment with the core at the middle so as to transmit pressuredirectly to the core at the proper point when a jack or blocks areengaged on the flat surface 22' in holding the heater in place under thehousing to be heated. Another advantage flowing from the provision of amiddle pole is that the path of the magnetic flux is shortenedproportionately and the operation of the heater is made more efficient.In this heater, as in the other, it is also contemplated to providehooks 20 to permit suspension of the heater on therear" axle housing.The housing [9' in this case as in the In operation, it will-be apparentthat the use I of chains or cables for suspension of the heater from the'housing, or the use of 'ajack or. blocks to support the heater underthe housing is in reality required only up to the time thatthe.

switch24 is closed and the coils l8- energized;

attraction. It is not necessary. therefore, to do anything more thanbring the 'aws l6 or I 6' into contact with the housing at the outset,because these jaws will be drawn into firm contact with .the housingjust as soon as the current is turned The present device, in addition tobeing useful in draining lubricant from housings, is also useful as agood means 01 checking the amount of lubricant present in a housing,because it can be applied to the housing long enough to drain all of thelubricant to the bottom, and then, when the plug at the sight opening,usually provided for the purpose of checking the level of lubricant, isremoved, one can tell immediately whether there is sufficient lubricantor whether some should be added to bring the level up to the opening. Inthat way there is a saving in .expense to the motorist because hesavesthe cost of what surplus lubricant might be put in and any repairbills that might arise from surplus lubricant working its way out of thehousing, and, on the other hand,

- he saves repair bills due to not having suilicient lubricant.

It is believed the foregoing description conveys a good understanding ofthe objects and advantages of my invention. The following claims havebeen drawn so as to cover all legitimate modifications and adaptations.

I claim:

l. A heater for application to a motor vehicle differential ortransmission housing to be heated comprising contact jaws for engagementwith the housing at spaced points, and meansfor inducing electromagneticflux passage of some frequency and alternating direction through thewall of said housing from one of the jaws to the other, whereby to heatthe housing.

2. A heater for application to a motor vehicle differential ortransmission housing to be heated comprising contact jaws for engagementwith the housing at spaced points, a core of magnetic materialcompleting a magnetic circuit between said contact jaws, whereby topermit the passage of magnetic flux of some frequency and alternatingdirection through the wall of said housing between the points of contactof the jaws therewith to heat the same, and means for inducing thepassage of magnetic flux of some frequency and alternating direction inthe circuit.

3. In combination, a rear axle differential housing having diiferentialgearing therein and axle sections connected with the gearing andreceived in bearings at opposite ends of the hous ment with the housingat opposite ends in the vicinity of the bearings, and means for inducingelectromagnetic flux passage of some frequency and alternating directionthrough the wall of said housing from one of the jaws to the other,whereby to heat the housing and transmit. heat through the bearings andaxle sections to the differential gearing.

4. In I combination, a rear axle differential housing havingdifferential gearing therein and axle sections connected with thegearing and received in bearings at opposite ends of the housing, aheater for heating the housing and gearing therein comprising contactjaws forengagement with the housing at opposite ends in the vicinity ofthe bearings, a core of magnetic material completing a magnetic circuitbetween said contact jaws, whereby to permit the passage of magneticflux of some frequency and alternating direction through the wall ofsaid housing between the points of contact of the jaws therewith to heatthe same and transmit heat through the bearings and axle sections to thedifferential'gearing, and means for inducing the passage of magneticflux of some frequency and alter nating direction in the circuit.

5. In combination, a rear axle differential housing having differentialgearing therein and axle sections connected with the gearing andreceived in bearings at opposite ends of the housing, a heater forheating the housing and gearing therein comprising means for applyingheat to the housing in the vicinity of said bearings, whereby to heatthe housing and at the same time transmit heat through the bearings andaxle sections to the differential gearing.

' 6. As a means for heating an object of magnetic material, contact jawsfor engagement with the object at spaced points, and means for inducingelectromagnetic flux passage of some frequency and alternating directionthrough the object from one of the jaws to the other, whereby to heatthe object.

'7. As a means for heating an object of magnetic material, contact jawsfor engagement with the object at spaced points, a core of magneticmaterial completing a magnetic circuit between said contact jaws,whereby to permit the passage of magnetic flux of some frequency andalternating direction through the object between the points of contactof the jaws therewith to heat the same, and means for inducing thepassage of magnetic flux of some frequency and altera device to beheated, comprising an electro-' magnetic core having object contactingportions to engage the object to be heated at spaced points thereon, oneor more coils surrounding the core for induction of electromagnetic fluxtherein, said coils being arranged to have electric current suppliedthereto so as to cause electromagnetic flux passage of some frequencyand alternating direction through the core and the object engaged by itscontact portions whereby to heat the latter, said core being attractedto the object magnetically during normal operation, whereby the same isself-supporting, and auxiliary supporting means for said device.

9. A portable electric heater of the character described for applicationto the raised bottom of a device to be heated, comprising anelectromagnetic core having object contracting portions to engage theobject to be heated at spaced points thereon, one or more coilssurrounding the core for induction of electromagnetic flux therein,

said coils being arranged to have electric current supplied thereto soas to cause electromagnetic flux passage of some frequency through thecore and the object engaged by its contact portions whereby to heat thelatter, a housing of suitable material enclosing the core and coils andhaving provision for supporting the heater by means of the housing, andmeans in the housing engaging a portion of the core to transmit thrustfrom the housing to the core and thence to the object engaged by thelatter.

10. As 'a heater, an electromagnet having a plurality of spaced jaws forengagement with a metallic object to be heated and means for inducingelectromagnetic flux passage through the jaws and object of somefrequency and alternating direction, whereby to cause heating of theobject. Y

'11. A heater forapplication to a housing to be heated comprisingcontact jaws for engagement with the-housing at spaced points, and meansfor inducing electromagnetic flux of a certain frequency through thewall of the housing from one of the jaws to the other, whereby to heatthe housing.

12. In combination, a rear axle difierential housing having difierentialgearing therein and axle sections connected with the gearing and re- Yceived in bearings at opposite ends of the housing, a heater for heatingthe housing and gearing therein comprising contact jaws for engagementwith the housing at opposite ends in the vicinity of the bearings, andmeans for inducing electro-' magnetic flux passage of some frequencythrough the wall of said housing from one of the jaws to the other,whereby to heat the housing and transmit heat through thebearings andaxle sections to the differential gearing.

13. As a means for heating an object of. magnetic material, contact jawsfor engagement with the object at spaced points, and means for inducingelectromagnetic flux passage of some frequency through the object fromone of the jaws to the other, whereby to heat the object.

l4. A portable electric heater of the character described, comprising anelectromagnetic core having object contacting portions to engage theobject to be heated at spaced points thereon, one

or more coils surrounding the core for induction or electromagneticfiux'therein, said coils being arranged to have electric currentsupplied thereto so as to cause electromagnetic flux passage of somefrequency through the core and the object engaged by its contactportions whereby to heat the latter, said core being attracted to theobject magnetically during normal operation, whereby the same isself-supporting, and auxiliary supanother to vary the spacedrelationship, and means for inducing electromagnetic flux passagethrough the core and jaws and through the wall of said housing wherebyto heat the latter.

17. In combination, a rear axle differential housing having differentialgearing therein and axle sections connected with the gearing andreceived in bearings at opposite ends of the housing, and a heatercomprising contact jaws adjustable toward and away from one another topermit placing the same in engagement with the housing at opposite endsin the vicinity of the bearings,

whereby to heat the housing and at the same time transmit heat throughthe bearings and axle sections to the differential gearing.

18. In combination, a rear axle difl'erential housing havingdifferential gearing therein and axle sections connected with thegearing and received in bearings at opposite ends of the housing, and aheater comprising a core of magnetic material having contact jaws inmagnetic circuit therewith adjustable relative to one another forengagement with the housing at opposite ends thereof, and means forinducing the passage of magnetic flux through the core and jaws wherebyto heat the housing.

19. As a means for heating difierent sized objects of .magnetic'permeable material, contact jaws-for engagement with spaced points ofthe object to be heated, said jaws being mounted for adjustment towardand away from one another so as to be adapted for application ondiflerent sized and different shaped objects, and a core with which saidadjustable jaws maintain a closed magnetic circuit in difierentpositions of adjustment, the circuit being closed bythe objectinterposed between the jaws, and said core having electrical means forinducing magnetic flux passage in the circuit for heating the object.

20, A portable heater of the character described comprising contact jawsfor engagement with' spaced points of a housing of magnetic permeablematerial, said jaws being mounted for adjustment toward and away fromone another so as to be adapted for application on different sized anddifferent shaped housings, and a core with which said adjustable jawsmaintain a closed magnetic circuit in different positions of adjustment,the

circuit being'closed by the housing interposed between the jaws, andsaid core having electrical means for inducing magnetic flux passage inthe circuit for heating the housing.

RAY A. BROWN.

